U.S. patent application number 13/214966 was filed with the patent office on 2012-02-23 for sand control well completion method and apparatus.
This patent application is currently assigned to SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Samyak Jain, PHILIP WASSOUF.
Application Number | 20120043079 13/214966 |
Document ID | / |
Family ID | 45593157 |
Filed Date | 2012-02-23 |
United States Patent
Application |
20120043079 |
Kind Code |
A1 |
WASSOUF; PHILIP ; et
al. |
February 23, 2012 |
SAND CONTROL WELL COMPLETION METHOD AND APPARATUS
Abstract
A technique includes running a sand control completion system
into a well, where the system includes at least one sensor, a
gravel packing service tool and a sand control section. The sand
control completion system is used to perform a gravel
packing-related operation in the well in which a slurry is
communicated downhole through the service tool to deposit gravel
near the completion section. The technique includes regulating the
gravel packing-related operation based at least in part on data
acquired by said at least one sensor and communicated to an Earth
surface of the well while the operation is being performed.
Inventors: |
WASSOUF; PHILIP; (London,
GB) ; Jain; Samyak; (Stafford, TX) |
Assignee: |
SCHLUMBERGER TECHNOLOGY
CORPORATION
SUGAR LAND
TX
|
Family ID: |
45593157 |
Appl. No.: |
13/214966 |
Filed: |
August 22, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61375977 |
Aug 23, 2010 |
|
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Current U.S.
Class: |
166/250.01 ;
166/51 |
Current CPC
Class: |
E21B 43/04 20130101;
E21B 47/007 20200501; E21B 31/00 20130101 |
Class at
Publication: |
166/250.01 ;
166/51 |
International
Class: |
E21B 43/04 20060101
E21B043/04; E21B 33/12 20060101 E21B033/12; E21B 31/00 20060101
E21B031/00; E21B 43/10 20060101 E21B043/10; E21B 47/09 20060101
E21B047/09 |
Claims
1. A method comprising: running a sand control completion system
into a well, the system comprising at least one sensor, a gravel
packing service tool and a sand control section; using the sand
control completion system to perform a gravel packing operation in
the well in which a slurry is communicated downhole through the
service tool to deposit gravel near the completion section; and
prior to the gravel packing operation, performing a given operation
in the well and regulating the given operation based at least in
part on data acquired by said at least one sensor and communicated
to an Earth surface of the well while the given operation is being
performed.
2. The method of claim 1, wherein said at least one sensor
comprises at least one pressure sensor adapted to acquire a
measurement of an overbalance pressure, the given operation
comprises the running of the sand completion operation into the
well, and the act of regulating the given operation comprises
selectively displacing weighted fluid at the Earth surface based at
least in part on the measurement.
3. The method of claim 1, wherein the running comprises running a
tubular work string into the well that has become stuck in the well
during the running, said at least one sensor comprises at least one
sensor adapted to acquire a measurement of a force exerted on the
string, the given operation comprises an operation to free the
string, and the act of regulating the given operation comprises
adjusting a force applied to the string at the Earth surface based
at least in part on the measurement.
4. The method of claim 1, wherein the given operation comprises an
operation to communicate a treatment fluid into the well using an
internal passageway of the service tool before a packer of the
lower completion system is set, the service tool has become stuck
in the well during the given operation, said at least one sensor
comprises at least one sensor adapted to acquire a measurement of a
pressure inside the internal passageway of the service tool, and
the act of regulating the given operation comprises from the Earth
surface, adjusting a rate at which the fluid is communicated into
the internal passageway to free the service tool based at least in
part on the measurement.
5. The method of claim 1, wherein the lower completion section
comprises a packer adapted to be set by fluid pressure, said at
least one sensor comprises at least one pressure sensor adapted to
acquire a measurement of a pressure of fluid near the packer, the
given operation comprises setting the packer, and the act of
regulating the given operation comprises controlling the pressure
from the Earth surface to set the packer based at least in part on
the measurement.
6. The method of claim 1, wherein the lower completion section
comprises a packer comprising a seal element to form an annular
seal when the packer is set, said at least one sensor comprises at
least one pressure sensor adapted to acquire a measurement of a
differential pressure across the seal element, the given operation
comprises a pressure test of the packer, and act of regulating the
given operation comprises performing the pressure test of the
packer based at least in part on the measurement.
7. The method of claim 1, wherein the running comprises running the
sand control completion system into the well on a tubular string,
said at least one sensor comprises at least one sensor adapted to
acquire a measurement of an acceleration or a force exerted on the
string, the given operation comprises a push/pull test of the
string, and the act of regulating the given operation comprises
performing the push/pull test based at least in part on the
measurement.
8. The method of claim 1, wherein the running comprises running the
sand control completion system into the well on a tubular string,
the sand control completion system comprises a packer comprising
slips, said at least one sensor comprises at least one sensor
adapted to acquire a measurement of an acceleration of the string,
the given operation comprises an operation to test whether the
slips of the packer are set, and the act of regulating the given
operation comprises performing the operation to test whether the
slips are set based at least in part on the measurement.
9. The method of claim 1, wherein the running comprises running the
sand control completion system into the well on a tubular string,
the service tool is adapted to be released from the lower
completion section in response to fluid pressure being communicated
to the service tool via an internal passageway of the string, said
at least one sensor comprises at least one sensor adapted to
acquire a measurement of a pressure inside the string near the
service tool, and the act of regulating the given operation
comprises controlling pressurization of the string from the Earth
surface to release the service tool from the lower completion
section based at least in part on the measurement.
10. The method of claim 1, wherein the running comprises running
the sand control completion system into the well on a tubular
string, said at least one sensor comprises at least one sensor
adapted to acquire a measurement of a differential pressure across
the service tool, and the act of regulating the given operation
comprises controlling an upward force applied to the string at the
Earth surface based at least in part on the measurement.
11. The method of claim 1, wherein said at least one sensor
comprises at least one sensor adapted to acquire a measurement of a
motion or a position of the service tool, the given operation
comprises locating the service tool, and the act of regulating the
given operation comprises determining a location of the service
tool based at least in part on the measurement.
12. The method of claim 1, wherein said at least one sensor
comprises at least one sensor adapted to acquire a measurement of a
swabbing induced pressure on the service tool, and the act of
regulating the given operation comprises regulating movement of the
service tool based at least in part on the measurement.
13. The method of claim 1, wherein the running comprises running
the sand control completion system into the well on a tubular
string, the operation comprises an operation to communicate a
multiple stage fluid flow comprising pickle stages downhole via the
string, said at least one sensor comprises at least one sensor
adapted to acquire a measurement indicative of a property of the
fluid flow, and the act of regulating the given operation comprises
controlling pumping of the fluid flow from the Earth surface based
at least in part on the measurement.
14. The method of claim 1, wherein the running comprises running
the sand control completion system into the well on a tubular
string, the operation comprises an operation to communicate a fluid
flow into the string to displace a given fluid from a given region
of the well, said at least one sensor comprises at least one sensor
adapted to acquire a measurement indicative of a fluid property in
the given region or a flow rate in the given region, and the act of
regulating the given operation comprises controlling pumping of the
fluid flow from the Earth surface based at least in part on the
measurement.
15. The method of claim 1, wherein said at least one sensor
comprises at least one sensor adapted to acquire a measurement of a
property of the well, the given operation comprises calibrating a
sand treatment model, and the act of regulating the given operation
comprises calibrating the sand treatment model based at least in
part on the measurement.
16. The method of claim 1, wherein said at least one sensor
comprises at least one sensor adapted to acquire a measurement
indicative of an unintended restriction present in the well, and
the act of regulating the given operation comprises performing
corrective action to remove the restriction.
17. The method of claim 1, wherein the operation comprises an
operation in which fluid is communicated into the well, said at
least one sensor comprises at least one sensor adapted to acquire a
measurement indicative of a region of the well in which fluid is
being lost during the operation, and the act of regulating the
given operation comprises selectively altering the operation based
at least in part on the measurement.
18. A method comprising: running a sand control completion system
into a well, the system comprising at least one sensor, a gravel
packing service tool and a sand control section; performing a
gravel packing operation in the well, the performing comprising
communicating slurry downhole through the service tool to deposit
gravel near the completion section; regulating at least one of
movement of the service tool and a screenout pressure based at
least in part on data acquired by said at least one sensor and
communicated to an Earth surface of the well while the gravel
packing operation is being performed.
19. The method of claim 18, further comprising: regulating roping
based at least in part on the data acquired by said at least one
sensor while the gravel packing operation is being performed.
20. The method of claim 18, further comprising: identifying
formation of an unintended opening in the sand control section
while the gravel packing operation is being performed.
21. The method of claim 18, further comprising: while the gravel
packing operation is being performed, planning an operation to be
conducted after conclusion of the gravel packing operation based at
least in part on the data acquired by said at least one sensor.
22. A method comprising: running a sand control completion system
into a well, the system comprising at least one sensor, a gravel
packing service tool and a sand control section; using the sand
control completion system to perform a gravel packing operation in
the well in which a slurry is communicated downhole through the
service tool to deposit gravel near the completion section; and
after the gravel packing operation, performing a given operation in
the well and regulating the given operation based at least in part
on data acquired by said at least one sensor and communicated to an
Earth surface of the well while the given operation is being
performed.
23. The method of claim 22, wherein the running comprises running
the sand control completion system into the well on a tubular
string, said at least one sensor comprises at least one sensor
adapted to acquire a measurement of a pressure, the given operation
comprises an operation to move the string to reposition the service
tool, and the act of regulating the given operation comprises
regulating pressure of an annulus that surrounds the string to
maintain slurry fluid inside the tubular string while the service
tool is being repositioned based at least in part on the
measurement.
24. The method of claim 22, wherein the running comprises running
the sand control completion system into the well on a tubular
string, said at least one sensor comprises at least one sensor
adapted to acquire a measurement of a force exerted on the string,
the given operation comprises an operation to move the string and
the string has become stuck in the well, and the act of regulating
the given operation comprises regulating a pulling force exerted on
the string to free the string based at least in part on the
measurement.
25. The method of claim 22, wherein the operation comprises an
operation in which fluid is communicated into the well, said at
least one sensor comprises at least one sensor adapted to acquire a
measurement indicative of a region of the well in which fluid is
being lost during the operation, and the act of regulating the
given operation comprises selectively altering the operation based
at least in part on the measurement.
26. A system usable with a well, comprising: a sand control
completion system comprising: a tubular string; a sand control
section, wherein the sand control section is adapted to be secured
to the string to be run into the well and installed in the well; a
gravel pack service tool adapted to be run downhole as a unit with
the sand control section and be released after the sand control
section is installed in the well to allow the gravel pack service
tool to move with respect to the sand control section; and at least
one sensor to be run downhole as part of the unit; and a surface
controller disposed at the Earth surface to communicate with said
at least one sensor during a gravel packing operation in which a
slurry is communicated downhole through the string and through the
service tool to deposit gravel near the sand control section, the
surface controller adapted to display information to an operator
indicative of at least one of a screenout pressure and an
unintended movement of the service tool during the gravel packing
operation based at least in part on the communication.
27. A system usable with a well, comprising: a sand control
completion system comprising: a tubular string; a sand control
section, wherein the sand control section is adapted to be secured
to the string to be run into the well and installed in the well; a
gravel pack service tool adapted to be run downhole as a unit with
the sand control section and be released after the sand control
section is installed in the well to allow the gravel pack service
tool to move with respect to the sand control section; and at least
one sensor to be run downhole as part of the unit; and a surface
controller disposed at the Earth surface to communicate with said
at least one sensor at least before a given operation that precedes
a gravel packing operation in which a slurry is communicated
downhole through the string and through the service tool to deposit
gravel near the sand control section, the surface controller
adapted to display information to an operator indicative of the
given operation during the given operation to allow the operator to
selectively perform corrective action in response thereto.
28. A system usable with a well, comprising: a sand control
completion system comprising: a tubular string; a sand control
section, wherein the sand control section is adapted to be secured
to the string to be run into the well and installed in the well; a
gravel pack service tool adapted to be run downhole as a unit with
the sand control section and be released after the sand control
section is installed in the well to allow the gravel pack service
tool to move with respect to the sand control section; and at least
one sensor to be run downhole as part of the unit; and a surface
controller disposed at the Earth surface to communicate with said
at least one sensor at least after a given operation that proceeds
a gravel packing operation in which a slurry is communicated
downhole through the string and through the service tool to deposit
gravel near the sand control section, the surface controller
adapted to display information to an operator indicative of the
given operation during the given operation to allow the operator to
selectively perform corrective action in response thereto.
Description
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application Ser. No.
61/375,977, entitled, "METHOD OF CONDUCTING A SAND CONTROL WELL
COMPLETION OPERATION," which was filed on Aug. 23, 2010, and is
hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The disclosure generally relates to a sand control well
completion method and apparatus.
[0003] Fluid producing and injection wells are often located in
subterranean formations that contain unconsolidated particulates
that can migrate out of the formation with the oil, gas, water, or
other fluid produced from the well. The production of such
particulates such as sand is undesirable because they may abrade
the production and surface equipment such as tubing, pumps, and
valves. In addition, the particulates may partially or fully clog
the well and reduce the fluid production which might ultimately
create the need for expensive remedial work.
[0004] Before a gravel pack operation is conducted, an overall job
plan typically is prepared in which information about the well is
used. This information typically is obtained from measurements
taken while the well was drilled as well as information from nearby
wells, if available. The information may include the depth of the
well; hole depths and diameters; downhole formation pressures to be
encountered; the amount of fluids that will likely need to be
pumped; the volume and type of gravel that will be needed; etc.
SUMMARY
[0005] In an embodiment of the invention, a technique includes
running a sand control completion system into a well, where the
system includes at least one sensor, a gravel packing service tool
and a sand control section. The sand control completion system is
used to perform a gravel packing operation in the well in which a
slurry is communicated downhole through the service tool to deposit
gravel near the completion section. The technique includes prior to
the gravel packing operation, performing a given operation in the
well and regulating the given operation based, at least in part, on
data acquired by the sensor(s) and communicated to an Earth surface
of the well while the given operation is being performed.
[0006] In another embodiment of the invention, a technique includes
running a sand control completion system into a well, where the
system includes at least one sensor, a gravel packing service tool
and a sand control section; and performing a gravel packing
operation in the well, where the performing includes communicating
slurry downhole through the service tool to deposit gravel near the
completion section. The technique includes regulating at least one
of movement of the service tool and a screenout pressure based, at
least in part, on data acquired by the sensor(s) and communicated
to an Earth surface of the well while the gravel packing operation
is being performed.
[0007] In another embodiment of the invention, a technique includes
running a sand control completion system into a well, where the
system includes at least one sensor, a gravel packing service tool
and a sand control section. The sand control completion system is
used to perform a gravel packing operation in the well in which a
slurry is communicated downhole through the service tool to deposit
gravel near the completion section. The technique includes, after
the gravel packing operation, performing a given operation in the
well and regulating the given operation based, at least in part, on
data acquired by the sensor(s) and communicated to an Earth surface
of the well while the given operation is being performed.
[0008] In another embodiment of the invention, a system includes a
controller that is disposed at the Earth surface and a sand control
completion system, which includes a tubular string, sand control
section, a gravel pack service tool and at least one sensor. The
sand control section is adapted to be secured to the string to be
run into the well and installed in the well, and the gravel pack
service tool is adapted to be run downhole as a unit with the sand
control section and be released after the sand control section is
installed in the well to allow the gravel pack service tool to move
with respect to the sand control section. The sensor(s) are also
adapted to be run downhole as part of the unit. The controller
communicates with the sensor(s) during a gravel packing operation
in which a slurry is communicated downhole through the string and
through the service tool to deposit gravel near the sand control
section. The controller is adapted to display information to an
operator indicative of at least one of a screenout pressure and an
unintended movement of the service tool during the gravel packing
operation based at least in part on the communication.
[0009] In another embodiment of the invention, a system includes a
controller that is disposed at the Earth surface and a sand control
completion system, which includes a tubular string, sand control
section, a gravel pack service tool and at least one sensor. The
sand control section is adapted to be secured to the string to be
run into the well and installed in the well, and the gravel pack
service tool is adapted to be run downhole as a unit with the sand
control section and be released after the sand control section is
installed in the well to allow the gravel pack service tool to move
with respect to the sand control section. The sensor(s) are also
adapted to be run downhole as part of the unit. The controller
communicates with the sensor(s) at least before a given operation
that precedes a gravel packing operation in which a slurry is
communicated downhole through the string and through the service
tool to deposit gravel near the sand control section. The
controller is adapted to display information to an operator
indicative of the given operation during the given operation to
allow the operator to selectively perform corrective action in
response thereto.
[0010] In yet another embodiment of the invention, a system
includes a controller that is disposed at the Earth surface and a
sand control completion system, which includes a tubular string,
sand control section, a gravel pack service tool and at least one
sensor. The sand control section is adapted to be secured to the
string to be run into the well and installed in the well, and the
gravel pack service tool is adapted to be run downhole as a unit
with the sand control section and be released after the sand
control section is installed in the well to allow the gravel pack
service tool to move with respect to the sand control section. The
sensor(s) are also adapted to be run downhole as part of the unit.
The controller communicates with the sensor(s) at least before a
given operation that proceeds a gravel packing operation in which a
slurry is communicated downhole through the string and through the
service tool to deposit gravel near the sand control section. The
controller is adapted to display information to an operator
indicative of the given operation during the given operation to
allow the operator to selectively perform corrective action in
response thereto.
[0011] Advantages and other features of the invention will become
apparent from the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram of a well illustrating a sand
control completion system according to some embodiments of the
invention.
[0013] FIG. 2 is a schematic diagram of the sand control completion
system illustrating a run-in-hole/washdown state of the system
according to some embodiments of the invention.
[0014] FIG. 3 is a schematic diagram of the sand control completion
system illustrating a packer set/test state of the system according
to some embodiments of the invention.
[0015] FIG. 4 is a schematic diagram of the sand control completion
system illustrating a squeeze/injecting state of the system
according to some embodiments of the invention.
[0016] FIG. 5 is a schematic diagram of the control completion
system illustrating a circulating state of the system according to
some embodiments of the invention.
[0017] FIG. 6 a schematic diagram of the control completion system
illustrating a reverse state of the system according to some
embodiments of the invention.
[0018] FIG. 7 is a flow diagram depicting a technique to control a
downhole operation prior to a gravel packing operation using at
least one sensor disposed on the sand control completion system
according to some embodiments of the invention.
[0019] FIG. 8 is a flow diagram depicting a technique to control a
gravel packing operation using at least one sensor disposed on the
sand control completion system according to some embodiments of the
invention.
[0020] FIG. 9 is a flow diagram depicting a technique to control a
downhole operation subsequent to the gravel packing operation using
at least one sensor disposed on the sand control completion system
according to some embodiments of the invention.
DETAILED DESCRIPTION
[0021] In the following detailed description, terms such as
`upper," "lower", "downhole," and the like are relative terms to
indicate the position and direction of movement of various
components shown in the drawings. Usually these terms are relative
to a line drawn perpendicularly downward through the center of the
borehole as would be the case in a straight, relatively vertical
wellbore. However, when the wellbore is highly deviated or
horizontal, such terms may refer to left or right, right to left,
or diagonal relationships as appropriate. Also, in the following
detailed description, various sensors and the measurements to be
taken by such sensors might be described with reference to one or
more figures but not in others. Such omissions are solely for the
purpose of providing clarity with the understanding that any
combination of sensors and measurements taken may be used without
departing from the spirit and scope of the invention.
[0022] Traditionally, after a gravel packing plan is finalized and
operations associated with the gravel packing plan begin, the
conventional gravel packing system provides relatively little
feedback at the Earth surface from which determinations may be made
regarding whether the operations are proceeding as planned.
Contrary to conventional arrangements, systems and techniques are
disclosed herein, which allow downhole parameters associated with
gravel packing-related operations to be monitored at the Earth
surface in real time or near real time so that appropriate actions
may be undertaken to regulate or control these operations as the
operations are occurring.
[0023] In the context of this application, the "real time or near
real time" communication of a downhole parameter measurement to the
Earth surface means that the data indicative of the measurement is
communicated from a downhole location in the well where the
measurement is acquired to equipment at the Earth surface within a
few seconds or minutes. As described herein, in accordance with
some embodiments of the invention, the real time or near real time
communication of the data uphole occurs at a sufficiently fast
enough rate to permit a downhole operation that influences or is
influenced by the measurement to be regulated or controlled using
equipment at the Earth surface based on the data.
[0024] FIG. 1 generally depicts a well, in accordance with some
embodiments of the invention. In general, as shown in FIG. 1, a
wellbore 14 traverses one or more formations and is illustrated in
FIG. 1 for this example, as being partially cased by a casing
string 16, which lines, or supports, at least part of the wellbore
14. In this manner, for the example that is depicted in FIG. 1, the
casing string 16 extends downhole from the Earth surface into the
wellbore 14, leaving a bottom portion of the wellbore 14 uncased.
It is noted, however, that the wellbore 14 may be entirely cased,
in accordance with other embodiments of the invention. Moreover,
although the wellbore 14 is illustrated in FIG. 1 and the following
figures as being a vertical wellbore, the wellbore 14 may be a
lateral or a deviated wellbore, in accordance with other
embodiments of the invention. It is noted that FIG. 1 depicts a
simplified schematic diagram of the well, in that various aspects
of the well, such as the casing shoe at the lower end of the casing
string 16, cement surrounding the casing string 16, etc., are not
depicted in FIG. 1.
[0025] FIG. 1 depicts a tubular work string 12 (a drill string, for
example) that extends downhole inside a central passageway of the
casing string 16; and at its lower end, the work string 12 contains
a tubing 18 that connects to a sand control completion system 10.
More specifically, at its lower end, the tubing 18 is connected to
a service tool assembly 20 of the sand control completion system
10, and for the example depicted in FIG. 1, the service tool 20
extends into a lower completion section 30 of the sand control
completion system 10.
[0026] In general, the lower completion section 30 includes a sand
control section 46 (a sand screen, a perforated pipe, a slotted
pipe, etc.), which for the example that is depicted in FIG. 1
extends into the uncased section of the wellbore 14 and includes a
shoe 47 at its bottom end. In addition to the sand control section
42, the lower completion section 30 includes a gravel pack packer
32, which, when radially expanded, or set, anchors itself to and
forms an annular seal with the casing string 16.
[0027] In general, the service tool 20 and the lower completion
section 30 are run downhole as unit into the well on the end of the
work string 12. Although the service tool 20 is initially secured
to the lower completion section 30, the service tool 20 is
constructed to be released from the lower completion section 30 and
controlled from the Earth surface of the well for purposes of
performing various gravel packing-related operations. One of these
gravel packing-related operations is the gravel packing operation
itself in which a gravel-laden slurry is communicated downhole, and
a carrier fluid exits the slurry to leave a filtering substrate of
gravel (not depicted in FIG. 1) deposited around the sand control
section 46.
[0028] More specifically, the carrier fluid returns to the Earth
surface via a path that extends through a passageway, or inner bore
23, of a wash pipe 22 of the service tool 20 and a casing annulus
24, which is the annular region between the tubing 18 and the
inside of the casing string 16. A cross-over assembly 25 of the
service tool 20 may be configured in a number of different states
(described below), among which is a state that allows fluid from
the washpipe inner bore 23 to cross over to the casing annulus
24.
[0029] In general, the cross-over assembly 25 controls fluid
communication between an inner bore 44 of the tubing 18; a
circulating port 40 of the lower completion section 30, which is in
fluid communication with an annulus 34 below the gravel pack packer
32; a circulating port 41 of the service tool 20, which is in fluid
communication with the casing annulus 24 above the gravel pack
packer 32; and the inner bore 23 of the wash pipe 22. The flow
path(s) through the cross-over assembly 25 are a function of the
particular state of the assembly 25, as further described
below.
[0030] For the state of the cross-over assembly 25 that is depicted
in FIG. 1 (which may be used for gravel packing), the cross-over
assembly 25 establishes fluid communication between an inner bore
44 of the tubing 18 and the annulus 34, and the cross-over assembly
25 establishes fluid communication between the inner bore 23 of the
wash pipe 22 and the casing annulus 24. In this manner, seals 42
and 43 (located on the outside of the service tool 20, for example)
form annular seals above and below the circulating port 40, which
forces fluid from the inner bore 44 of the tubing 18 through the
cross-over assembly 25 and into the annulus 34. The circulating
port 40 may be isolated with seals (not shown) when the production
tubing (not shown) is run in order to prevent production through
the circulating port 40. A port closure sleeve (not shown) may also
be used to close the circulating port 40 on pull out of the hole
(POOH) of the service tool 20 in order to isolate the well and
prevent fluid loss. Other embodiments may also use multiple valves
in the service tool 20 to enable crossover flow. These valves can
be actuated using a number of different mechanisms, including
hydraulically with the application of well pressure; mechanically
with an intervention tool, or by manipulation of work string 12;
and electrically with wire, wireless assemblies, or fiber
optics.
[0031] When the lower completion section 30 and the service tool 20
are run together via the work string 12 into the well, the lower
completion section 30 is positioned at the desired location, and
then the gravel pack packer 32 is set, which firmly secures the
lower completion section 30 to the casing string 16 and forms an
annular seal. As non-limiting examples, the gravel pack packer 32
may be a weight set packer or a hydraulically set packer. As
another example, in accordance with some embodiments of the
invention, the gravel pack packer 32 may be set by physically
manipulating the work string 12.
[0032] After the gravel pack packer 32 has been set, the service
tool 20 may be released from the lower completion section 30 to
perform various gravel packing-related operations, such as the
gravel packing operation itself, as well as operations that occur
before and after the gravel packing operation.
[0033] For purposes of establishing a real time or near real time
communication path between sensors (described below) of the sand
control completion system 10 and Earth surface-disposed monitoring
equipment 100 (herein called the "surface equipment 100"), the work
string 12 includes a control station 50. Depending on the
particular implementation, the control station 50 may be part of
the service tool 20 or may be disposed on another part of the work
string 12. The control station 50 may include a processor (one or
more microprocessors and/or microcontrollers, for example), memory
and a power and telemetry module to allow communication between
downhole sensors and the surface monitoring equipment 100. The
control station 50 may be used to process multiple readings from
the sensors and communicate the processed information to the Earth
surface, and the control station 50 may be used to receive commands
communicated from the Earth surface for purposes of controlling
certain downhole sensors. In addition, the control station 50 may
communicate signals to components in the well that automatically
change treatment of the well including 1) partially or fully
opening/closing valves to control flow rates and pressures in the
well 14; or 2) stopping movement or rate of movement of the service
tool 20. The control station 50 may also include various additional
sensors (pressure, temperature, acoustic, etc) that may be used to
acquire measurements that are communicated in real time or near
real time to the Earth surface, in accordance with some embodiments
of the invention. The sensors of the sand control completion system
10 are linked to the control station 50 by either a wired or
wireless telemetry system, depending on such factors as the
distance between the sensor and the control station 50, space
limitations, and the like.
[0034] In general, the well contains at least part of a
communication path 52 between the downhole control station 50 and
the surface monitoring equipment 100. As a non-limiting example,
the communication path 52 may include at least one fiber optic
cable that is connected to the control station 50 and extends to
the Earth surface via the work string 12, for example. As another
non-limiting example, the communication path 52 may be formed from
one or more electrically conductive wires that are disposed in the
string 12 (for example, the string 12 may be a wired drill pipe).
However, the communication path 52 may be formed at least in part
from a wireless communication path, in accordance with other
embodiments of the invention. In this manner, as non-limiting
examples, this wireless communication path may use such wireless
communication techniques as acoustic communication, electromagnetic
(EM) communication, pressure pulse communication, etc. Thus, many
variations are contemplated and are within the scope of the
appended claims.
[0035] The surface monitoring equipment 100 may take on numerous
different forms, depending on the particular embodiment of the
invention. In general, the surface monitoring equipment 100 may be,
in accordance with some embodiments of the invention, a
processor-based machine, which contains a processor 102 (one or
more microcontrollers and/or microprocessors, as non-limiting
examples) that executes machine executable instructions that are
stored in a non-transitory memory 104 (a semiconductor memory, an
optical memory, a magnetic storage-based memory, etc., as
non-limiting examples) for purposes of processing sensor or
sensor-derived measurements that are communicated to the Earth
surface by the control station 10 in real time or near real
time.
[0036] In this manner, in accordance with some embodiments of the
invention, using this execution of software, the surface monitoring
equipment 100 is constructed to provide (on a monitor, or display
106, for example) indications of direct measurements and indirect
measurements of various downhole parameters to a surface operator.
Based on these measurements, the surface operator may then take the
appropriate measures, or remedial actions, to control or regulate
downhole operations to achieve the desired results.
[0037] As non-limiting examples, the sensors of the sand control
completion system 10 may be constructed to directly or indirectly
measure, alone or in combination, one or more of the following:
pressure, temperature, force, torque, density, rheology, pH, flow
rate, acoustic energy, seismic energy, acceleration, gravel pack
logging images and/or other downhole properties. These measurements
or information based on these measurements are communicated to the
Earth surface in real time or near real time via the control
station 50 and its associated telemetry system (e.g., a telemetry
system including the communication path 52) in order to allow an
operator at the Earth surface to monitor an ongoing downhole
operation; control or regulate the operation in real time or near
real time; determine whether a given downhole operation is
proceeding according to plan; make decision regarding corrective
actions, if any, which should be taken; and monitor these
corrective actions, as just a few non-limiting examples.
[0038] As non-limiting examples, the corrective actions that may be
taken at the Earth surface of the well based on the information
that is communicated uphole from the sand control completion system
10 may include actions to regulate a fluid pumping rate, regulate
the introduction of fluid stages, regulate the volumetric amounts
of certain fluids that are introduced into the well, time the
introduction of fluid stages, regulate gravel delivery (start, end
and/or concentration, as examples), regulate a force that is
applied at the Earth surface to the work string 12, regulate
manipulation (turning, up/down movement, etc.) of the work string
12, regulate an amount of weight placed on the work string 12,
regulate travel of the work string 12, and so forth.
[0039] Examples of specific sensors of the sand control completion
system 10, measurements that may be acquired by the sensors of the
sand control completion system 10 and the general uses of these
measurements for purposes of controlling downhole operations are
next described below.
Pressure Measurements
[0040] In accordance with some embodiments of the invention, the
sand control completion system 10 may contain sensors to measure
pressures at various downhole locations. For example, in accordance
with some embodiments of the invention, the sand control completion
system 10 includes one or more of the following pressure sensors: a
pressure sensor 60 that is located inside the tubing 18 and
measures the pressure within the work string inner bore 44; a
pressure sensor 62 that is located outside the tubing 18 and
measures the pressure within the casing annulus 24; a pressure
sensor 64 that is located on the outside of the wash pipe 22 and
measures pressure in the annulus between the sand control assembly
46 and the wash pipe 22; a pressure sensor 66 that is located on
the inside of the wash pipe 22 and measures the pressure inside the
wash pipe 22; and a pressure sensor 68 that is located above the
sand control section 46 to on the lower completion section 30 to
measure pressure in the annulus 34. The sand control completion
system 10 may also include pressure sensors 70 that are disposed in
a distributed fashion on the lower completion section 30 along the
outside of sand control section 46 to acquire pressure measurements
along the sand control interval. Moreover, the sand control system
10 may contain a pressure sensor 72 that is disposed on the lower
completion section 30, near the shoe 47 and below the lower
completion section 46 to measure pressure below the sand control
section 30. The sensors may be distributed discretely or
continuously along the service tool string 20 and/or the lower
completion section 30 at the locations discussed above.
[0041] Thus, the arrangement that is depicted in FIG. 1 differs
from conventional arrangements in that the sensors 70 may be
installed along the length of the sand control section 46 and
accessed in real time or near real time in connection with a gravel
packing-related operation. The sensors 70 installed along the
length of the sand control assembly 46 are connected via a cable 72
to a female component 74a of an inductive coupling 74 that is
mounted below the gravel pack extension on the outer completion
section 30, as shown in FIG. 1. A proximate male component 74b is
mounted on the service tool 22, and this component 74b is coupled
(by a cable, for example) to the control station 50. In other
embodiments of the invention, wireless connections may be used
instead of, or in combination with, cable connections to
communicate between the sensors along on the screens, the control
station mounted above the service tool and the surface.
[0042] The above-disclosed pressure sensors of the sand control
system 10 may allow various pressures to be transmitted to the
Earth surface and observed in real time or near real time such that
appropriate real time/near real time actions may be taken from the
Earth surface. As non-limiting examples, the pressure measurements
may include rate of change measurements with respect to time and
volume as well as measurements that hydrostatic pressures and
differential pressures to be derived. Moreover, the pressure
differentials may be used for purposes of calculating a friction
pressure.
[0043] As a more specific example, during static conditions when
fluid is not being pumped from the Earth surface, downhole pressure
measurements indicate whether the downhole fluid pressure is within
a suitable range to control the well. If the pressure reading is
too low indicating an underbalanced condition, then heavier fluid
may be pumped from the surface. If the pressure reading is too high
indicating an overbalanced condition where formation fracturing
might occur, then a lighter fluid may be pumped from the
surface.
[0044] Other exemplary operations that may benefit from the
pressure sensors of the sand control completion system 10 include
an operation in which fluid is pumped from Earth surface in order
to set the gravel pack packer 32 within the casing string 16. In
this manner, pressure readings from the sensor 60 may indicate
whether the pressure is too low to set the gravel pack packer 32
and if so, the pressure can be increased. Once the gravel pack
packer 32 has been set, a packer element test may be conducted in
which a pressure measurement is taken below the packer 32 with the
sensor 64. If pressure is observed below the gravel pack packer 32,
then a leak is indicated; and setting of the gravel pack packer 32
is attempted again, or the gravel pack packer 32 is replaced. If
pressure is not indicated, then the gravel pack packer 32 was
seated and sealed properly. Other exemplary pressure measurements,
discussed later in more detail, may be taken when the well is in a
dynamic condition, i.e., when fluid is being pump from the surface
and there is fluid flow through the system.
[0045] Additional pressure measurements maybe taken downhole via
the pressure sensors of the sand control completion system 10 and
communicated uphole to monitor operations in real or near real time
in order to take remedial action, if needed. For example, various
downhole components that are subject to differential pressure may
be provided with pressure sensors across the differential and
monitored so that the pressure rating of such devices are not
exceeded during pumping operations.
[0046] For example, the sensor 62 above the packer 32 and the
sensor 68 below the gravel pack packer 32 may be monitored in real
time so as not to exceed the pressure rating of the packer 32. If
the pressure on the gravel pack packer 32 as detected based on
measurements from sensors 68 and 60 reaches a predetermined level,
then steps in real or near real time may be taken to reduce the
pressure on the packer 32. These steps may include reducing the
rate and pressure of fluid being pumped at the Earth surface. Other
examples of other components where differential pressure
measurements may be taken include inside and outside the service
tool 20 and across the fluid loss control seals 42 and 43. The sand
control system 10 may include a formation isolation valve, and
pressure sensors may sense pressures above and below the valve, in
accordance with some embodiments of the invention.
[0047] In addition, the sensor 68 may be positioned below the
circulating port 40 so that pressure measurements can be made
during the gravel packing operation. If pressure during the gravel
packing operation exceeds a predetermined level, then the rate and
pressure of fluid pumped from the Earth surface may be reduced to
prevent pressure from exceeding the collapse rating. In addition,
pressure measurements may be taken during swabbing. While the
service tool 20 is adjacent the gravel pack packer 32, the pressure
below the packer 32 decreases when the service tool 20 is moved
upwards in relation to the packer 32. The sensor 64 or the sensor
68 may be used to monitor the pressure of the fluid within the
annulus 34 to ensure that the observed pressure does not fall below
the fluid pressure within the reservoir for the wellbore 14. If the
observed pressure drops below a certain level, then movement of the
service tool 20 may be stopped to allow the downhole pressure to
equalize, or the rate of the movement of the service tool 20 may be
reduced in order to decrease the swabbing effect of such
movement.
[0048] Once the service tool 20 is positioned in the wellbore 14
and the gravel pack slurry is pumped downhole, the sensor 64 may be
monitored to ensure that the fluid pressure within the annulus 34
does not exceed the reservoir fracture pressure during a gravel
operation. If the sensor 64 records such an elevated pressure
reading, then the rate of the slurry flow may be reduced or chokes
at the Earth surface of the well may be fully or partially opened.
For fracturing treatments, the sensor 64 may also be monitored to
ensure that fluid pressure within the annulus 34 does not fall
below the reservoir fracture pressure. If the pressure sensor 64
records a measurement falling below a predetermined pressure level,
then the pressure may be increased within the annulus 34 by
increasing flow rate or chokes at the surface or in the well may be
fully or partially closed.
[0049] The pressure sensors may be used to monitor other
parameters, in accordance with many potential embodiments of the
invention. In real time or near real time, for example, pressure
may be monitored across downhole components. Therefore, if the
measured pressure is higher than a rating (a burst or collapse
rating, as examples) for the component, then the surface pump rate
may be decreased or a surface choke may be opened to maintain the
component within the appropriate operating envelope. The
differential pressure across the gravel pack packer 32 may also be
monitored. In this manner, the sensor 68 may be used as well as
sensor on top of the wash pipe 22 to ensure that the collapse
pressure of the blank pipe ensure is not exceeded.
[0050] As another example, the pressure sensors may be used to
observed friction pressures throughout the system. For example,
packing mechanisms, fluid changes, screen plugging, etc. may be
monitored and compared with expected trends. If different,
corrective action may then be taken to adjust the flow rate and/or
choke pressure from the Earth surface. If necessary, the current
operation may be stopped and reversed out. The pressure sensors may
also be used to calibrate design models to match friction pressures
in real time or near real time and facilitate better predictions
for future events.
[0051] The pressure sensors of the sand control completion system
may also be used to detect the arrival of different stages in a
multiple stage fluid treatment process. In this manner, the
pressure sensors 64 and/or 70 may sense fluid pressure at various
points downhole to identify the arrival of the different stages.
These measurements may also be used to estimate roping such that
the volumetric calculations performed at the Earth surface may be
adjusted to take this into account.
[0052] The pressure sensors of the sand control completion system
10 may also be used to regulate a screenout pressure, as further
described below.
Fluid Property Measurements
[0053] In accordance with some embodiments of the invention, the
sensors that are disposed on the sand control completion system 10
may acquire measurements of various fluid properties, such as
density, rheology, pH, etc., as a non-limiting list of examples.
These sensors may be disposed at various locations of the sand
control completion system 10, such as, as non-limiting examples,
above the service tool 20, on the service tool 20 and on the lower
completion section 30 at various points along the sand control
interval. In accordance with some embodiments of the invention,
these sensors may acquire distributed measurements along the entire
sand control interval.
[0054] For example, in accordance with some embodiments of the
invention, at least some of the sensors 70 along the sand control
section 46 may be fluid property-sensing sensors 70 (replacing or
in addition to the other sensors, which are disclosed herein). The
fluid property-sensing may be used to identify the presence of acid
during a cleanup treatment with an acidic treatment fluid, for
example. For effective cleanup, the acidic treatment fluid should
cover the entire interval selected for the cleanup treatment.
However, the acidic treatment fluid may divert preferentially
through open perforations or highly conductive open hole sections
and thus, not achieve an effective cleanup. As a more specific
example, the sensors 70 may be constructed to measure pH and
identify, in real time, where the acid is going and enable the
treatment to be better targeted.
[0055] In this manner, the acidic treatment fluid may be pumped
through the annular bore 44 of tubing 18, through the circulating
port 40 and into the annulus 34. The acidic treatment fluid flows
into the perforations or fractures in the casing string 16 and into
the surrounding reservoir. If the wellbore 14 is uncased and is
thus, an open hole wellbore, then the acidic treatment fluid flows
directly into high permeability zones in the reservoir walls that
surround the wellbore 14. If there is a high permeability zone, for
example, adjacent an upper portion of the sand control section 46,
then the acidic treatment fluid may not treat the interval of the
reservoir adjacent the lower portion of the sand control section
46. In such a situation, the pH sensors positioned along the upper
portion of the sand control section 46 measure a higher acidic
readings, as compared to the pH sensors that are positioned along a
lower portion of the sand control section 46.
[0056] In response to such pH readings, the appropriate may be
taken at the Earth surface of the well such as the use of
mechanical or chemical diversion to temporarily block the
conductive sections. After the temporary block, acidic treatment
fluid may be pumped to force the acidic treatment fluid along the
remainder of the interval, for example the interval adjacent the
lower section of the sand control assembly 46, and ensure an
effective cleanup. The chemical or mechanical diversion may include
pumping viscoelastic diverting acid (VDA), which forms a gel on
contact with formation fluids or mechanical ball sealers, which
temporarily plug and divert the acid, among other options. When
pumped, the VDA or mechanical ball sealers flow thru the conductive
sections and form a blocking gel or mechanical ball sealer blockage
to limit flow through the conductive sections.
[0057] The pH sensors of the sand control completion system 10 may
then be used to observe, from the Earth surface, various problems
that occur downhole in real time or near real time so that
corresponding corrective action may be undertaken to address these
problems. For example, the sand control completion system 10 may
include a pH sensor on the service tool 22 above the gravel pack
packer 32 for purposes of detecting the arrival of the acid in a
work string pickle. In this manner, if the pH reading acquired by
this pH sensor indicates a detected acidity, then pumping may be
ceased, and the acid may be reversed back the Earth surface.
[0058] As another example, fluid properties in the wellbore region
during a filter cake removal or acid treatment may also be
monitored. If the fluid is not being delivered to the required
zones or areas, a diverter (a mechanical or chemical diverter) may
be pumped to ensure that full coverage is achieved. For this
purpose, the sensors may be disposed along the sand control
assembly 46 and possibly along the wash pipe 22. As another
example, the fluid properties in the wellbore 14 may be measured to
ensure complete displacement of fluids. If the measurements
indicate the presence of a previous fluid stage, then pumping may
be increased at a faster rate in order to more effectively displace
the fluid.
[0059] It is also possible to rotate the work string 12 from the
Earth surface in some situations to improve displacement. For these
measurements, sensors along the sand control assembly 46 or wash
pipe 22 may be used to detect the fluid properties and ensure that
full displacement has occurred. As yet another example, design
models may be calibrated to match bottom hole conditions in real
time using bottom hole fluid properties derived from the sensors
for purposes of facilitating better predictions for future
events.
Temperature Measurements
[0060] The sand control completion system 10 may contain, in
accordance with some embodiments of the invention, sensors to
acquire distributed temperature measurements and/or measurements at
discrete downhole locations. The temperature readings from the
sensors may be monitored in real time or near real time at the
Earth surface before, during and after the gravel pack-related
operations to verify whether the operations are proceeding
according to plan and if not, whether remedial steps should be
taken. Such temperature measurements may be direct measurements,
may be taken over time, and may, in general, be functions of the
amount of fluid pumped downhole.
[0061] In this manner, a wide range of temperature measurements may
be acquired by temperature sensors of the sand control completion
system 10, such as direct measurements and rates of change of
temperature with respect to time and volume. Moreover, distributed
temperature measurements, similar to distributed temperature
sensing (DTS) measurements may be made, in accordance with some
embodiments of the invention.
[0062] As a more specific non-limiting example, during circulation,
temperature measurements taken along the wellbore 14 may show a
decrease in temperature at certain points, which would indicate
that fluid is being lost at nearby locations. In response to such
reduced temperature readings, remedial action may be taken such as
introducing loss control pills into well; mechanically or
chemically diverting fluid; or stopping, re-designing, or
continuing with the operation. In accordance with some embodiments
of the invention, the sensor 68 and/or at least some of the sensors
70 (replacing or in addition to the other sensors, which are
disclosed herein) may be temperature sensors. These temperature
sensors may, for example measure temperatures during fracturing
treatments, which indicate fluid flow information; and if
predetermined temperatures are reached, zones may be isolated and
separate treatments may be performed in other zones.
[0063] The temperature along the wellbore 14 may also be measured
after a given treatment. In this manner, a technique called "the
warmback technique" may be used to identify specific zones that are
taking fluid during a treatment so that the zones may be isolated.
Moreover, design models may be calibrated to match temperatures in
real time and facilitate better predictions for future events.
Force/Displacement Measurements
[0064] In some embodiments of the invention, sensors of the sand
control completion system 10 may be used to measure the
displacement of the sand control completion system 10 and/or the
forces that are acting on the system 10, such as tension, stress,
strain, torque, etc. These types of sensors are commonly referred
to as strain gauges. Such physical measurements may be made using a
strain sensor 60 (replacing or in addition to the other sensors,
which are disclosed herein) that is located on the service tool 20
above the gravel pack packer 32 and a strain sensor 64 (replacing
or in addition to the other sensors, which are disclosed herein)
that is located on the wash pipe 22. Additional sensors that are
constructed to acquire tension measurements may be disposed on the
service tool 20 between the sensor 60 and the sensor 64.
[0065] Force measurements that are acquired taken by the strain
sensors during the gravel pack operation may be monitored to
determine whether the operation is proceeding according to the plan
and if not, whether remedial actions need to be taken. For example,
the sensor 72 (replacing or in addition to the other sensors, which
are disclosed herein) at the bottom of the lower completion section
46 may be a strain sensor. For this example, if the sensor 72
indicates a sudden increase in compression force while the service
tool 20 is being run into wellbore 14 with the lower completion
section 30, the sudden increase indicates that a restriction has
been encountered. If so, and if wellbore 14 is an openhole
wellbore, fluid may be pumped from the Earth surface to eliminate
the restriction with the service tool 20 being raised and lowered
as appropriate. If the service tool 20 becomes stuck in the
wellbore 14, the above-disclosed strain sensors may be monitored at
the Earth surface while applying pulling and rotational forces from
the Earth surface to ensure that the forces that are exerted on
service tool 20, the lower completion section 30 and in general,
the components of the sand control completion system 10, do not
exceed equipment failure limitations.
[0066] The measurement of the forces acting on the work string 12
and the sand control completion system 10 may be used to control
other operations, in accordance with other embodiments of the
invention. For example, if the work string 12 becomes stuck, the
work string 12 may be manipulated while ensuring in real time or
near real time that equipment limitations are not exceeded by
adjusting the surface hook load. As another example, the sensors of
the sand control completion system 10 may be used to measure the
tension and/or compression on downhole tools, such as the gravel
pack packer 32 and the service tool 20. In this manner, the surface
hook loads may be adjusted to attain the correct
tension/compression values on downhole tools for their required
operation. As another example, small forces may be measured from
collet indications that may be observed on the Earth surface to
confirm the position of the service tool 20. If the service tool 20
is in the wrong position, then the work string 12 may be
manipulated to re-position the tool. The forces on the service tool
20 may be observed during pumping. In this regard, if the service
tool 20 begins to move upwardly out of position due to the pressure
below, then additional weight may be set down on the service tool
20 from the surface to keep it in place. Moreover, design models
may be calibrated to match the strain in real time or near real
time and facilitate better predictions for future events.
[0067] In accordance with some embodiments of the invention, the
sand control completion equipment 10 may include sensors on the
service tool 20 that are constructed to acquire measurements that
are indicative of the movement of the service tool 20. Depending on
the particular embodiment of the invention, the sensors may
directly measure the position of the service tool 20 and/or the
sensors may indirectly measure the position of the service tool 20.
As a more specific example, in accordance with some embodiments of
the invention, these sensors may be accelerometers, and the sensor
60 (replacing or in addition to the other sensors, which are
disclosed herein) may be an accelerometer that acquires a
measurement of the acceleration of the service tool 20. The second
integral of the acceleration with respect to time may be used for
purposes of determining displacement of the service tool 20.
Depending on the particular embodiment of the invention, the sensed
acceleration and/or the calculated displacement may be communicated
to the Earth surface from downhole in real time or near real time
so that the communicated measurements may be monitored at the Earth
surface to determine whether a gravel pack-related operation is
proceeding as planned (i.e., for purposes of determining whether
corrective action needs to be taken).
[0068] For example, after the gravel pack packer 32 has been set
within the casing string 16, a test may be performed to determine
whether the setting is sufficient to hold the packer 32 and the
connected service tool 20 firmly in place. In conducting such a
test, the hook load on the work string 12 may be increased and
decreased during a push/pull test. If the sensor 60 indicates
movement of the service tool 20 and the connected gravel pack
packer 32, this movement in turn indicates in real time or near
real time at the Earth surface that the gravel pack packer 32 has
not been set properly and additional pumping pressure is needed to
set the packer 32. Therefore, pumping pressure may be increased to
set the gravel pack packer 32 before proceeding forward with a
treatment.
[0069] In addition, the sensor 60 may be used to measure
acceleration and/or displacement to more accurately place the
service tool 20 into position with respect to the lower completion
section 30, which may be relatively difficult to otherwise
determine from the Earth surface because of the pipe stretch. After
the gravel pack packer 32 is set, the service tool 22 may be
physically disconnected from the packer 32. The service tool 22 may
then be moved up and down in relation to the gravel pack packer 32
to place the seals 42 in the appropriate positions for various flow
paths and with respect to the circulating port 40. For example, the
seals 42 may be positioned above and below the circulating port 40
for purposes of providing a flow path from the tubing inner bore 44
through the circulating port 40 to the annulus 34. The slurry may
then be pumped into the annulus 34 during the gravel treatment. The
position of the service tool 22 with respect to the circulating
port 40 may be determined based on displacement measurements from
the sensor 60.
[0070] Also during the gravel pack pumping operation, the
measurements from the sensor 60 may be used to indicate whether,
for example, the service tool 20 is moving out of position due to
pressure below the service tool 20. If so, the position of the
service tool 20 may be adjusted in real time or near real time by
applying additional hook load from the Earth surface.
Torque Measurements
[0071] The sand control completion system 10 may include sensors to
measure torque such that the measured torque may be observed in
real time or near real time at the Earth surface, in accordance
with embodiments of the invention. For example, the sand control
completion system 10 may contain a torque sensor on the service
tool 20, which acquires a torque measurement for the scenario in
which the lower completion section 30 has become stuck and a
rotational force is being applied to the work string 12 in an
attempt to rotate the lower completion section 30. The measured
torque may be monitored at the Earth surface in real time or near
real time for purposes of controlling the torque that is applied at
the Earth surface to avoid exceeding downhole equipment
limitations.
[0072] As non-limiting examples, the torque sensors may be disposed
above the service tool 20 and may be disposed on the shoe 47 at the
bottom of the string 12. The torque may also be measured at the
service tool 20 for purposes of identifying when the service tool
20 begins rotating such that the required number of turns of the
work string 12 may be observed at the Earth surface in real time or
near real time. For example, such turning of the work string 12 may
be used for purposes of setting the gravel pack packer 32, testing
a particular position, etc. As another non-limiting example, the
rotation may also be used and monitored for purposes of releasing
the gravel pack packer 32.
Imaging Measurements
[0073] The sand control completion system 10 may contain an imaging
sensor 80 (shown in FIG. 1 as being located in this non-limiting
example near the bottom of the wash pipe 22 for purposes of
acquiring a pack log, which may be viewed in real time or near real
time from the Earth surface. As non-limiting examples, the sensor
80 may be a neutron or gamma ray-based imaging sensor for purposes
of acquiring a surrounding image of the gravel pack as the service
tool 20 is moved up and down. The sensor 80 may be a sonic, or
acoustic, sensor, in accordance with other implementations.
[0074] Using the sensor 80, the gravel pack may be logged in real
time or near real time and observed from the Earth surface at the
end of the gravel packing operation to ensure the presence of a
sufficient coverage of the gravel around the sand control section
46. If sufficient coverage has been obtained, then the service tool
20 is pulled out of hole. If however, the sensor 80 indicated
inadequate coverage, then corrective action may be taken such as a
top-off job, a job that involves pumping resin consolidation
treatment downhole, screen isolation or similar remedial action to
prevent sand production from unpacked areas.
Acoustic/Seismic Measurements
[0075] The sand control completion system 10 may, in general,
include one or more acoustic or seismic sensors that are disposed
along the service tool 20 or along the sand control section 46 for
purposes of obtaining other real time or near real time downhole
acoustic and/or seismic measurements in connection with gravel
packing-related operations. For example, such sensors may be used
to measure the downhole vibration at the service tool 20 for
purposes of identifying arrival of proppant at the service tool 20
to indicate any roping in the work string 12. Volumetric
calculations may then be adjusted while the gravel slurry is being
pumped. The downhole vibration along the sand control section 46
may also be observed at the Earth surface in real time or near real
time to identify packing trends (e.g., alpha/beta, slurry pack,
etc.) to indicate the height of the alpha wave or bridge forming.
Based on the real time or near real time observations from the
Earth surface, the flow rate and/or choke pressure may be regulated
to ensure the correct alpha wave height and prevent bridging.
Flow Rate Measurements
[0076] The sand control completion system 10 may contain one or
more flow rate sensors, in accordance with some embodiments of the
invention. In this manner, the flow rate sensors may be disposed
along the sand control section 47 discretely or disposed to acquire
a distributed measurement, depending on the particular
implementation. Using flow rate sensors, the flow rate along the
wellbore region may be measured and monitored in real time or near
real time from the Earth surface. Using these measurements, the
location of any losses in the system may be identified and targeted
with loss control pills or similar treatments. Therefore, such
corrective action minimizes losses and maximizes the potential
success of the treatment.
[0077] The above-described sensors are examples of a few sensors
that may be disposed on the sand control completion system 10 for
purposes of allowing downhole parameters to be remotely observed at
the Earth surface in real time or near real time, in accordance
some of the many potential embodiments of the invention. As yet
another example, in accordance with some embodiments of the
invention, the sensors to monitor downhole parameters may be formed
from downhole tools, such as a packer, a service tool, a fluid loss
control device, etc. This feedback may be used to identify and
record tool position, verify tool activation, etc. In this manner
any tool, typically referred to as an "intelligent" tool, may be
used to provide this feedback.
[0078] The cross-over assembly 25 may be configured in various
states, depending on the particular operation being performed. FIG.
2 generally depicts a state of the cross-over assembly 25 when
configured for a run-in-hole or washdown state in which a flow 200
may be communicated from the inner bore or passageway of the tubing
18 down through the wash pipe 22 and out through the bottom end of
the shoe 47, as depicted in FIG. 2. Thus, in this state, the
circulating ports 40 and 41 are closed.
[0079] FIG. 3 depicts a state of the cross-over assembly 25 for the
packer set/test position. In this state, the cross-over assembly 25
establishes fluid communication between the inner bore, or
passageway, of the tubing 18 and the inner bore 23 of the wash pipe
22, with communication through the circulating ports 40 and 41
being closed.
[0080] FIG. 4 depicts the cross-over assembly 25 in a state for
squeeze/injecting. In this regard, as shown in FIG. 4, in this
state, the cross-over assembly 25 blocks fluid communication
between the inner bore 23 of the wash pipe 22 and the inner bore or
passageway of the tubing 18 and allows communication through the
circulating port 40. Thus, as depicted by the flows 204, fluid may
be communicated through the inner bore of the tubing 18, through
the circulating port 40 and into the annulus 34.
[0081] FIG. 5 depicts a state of the cross-over assembly 25 that
may be used to establish a flow 210 that is used in the pumping of
the gravel slurry and recovery of the gravel slurry fluid during a
gravel packing operation. In this regard, in this state, the
cross-over assembly 25 permits a flow 210 as depicted in FIG. 5
through the following path: from the inner bore or passageway of
the tubing 18, through the circulating port 40, into the annulus 34
(where the gravel is deposited), through the lower end of the wash
pipe 22 (where the fluid from the gravel slurry returns), through
the cross-over assembly 25, through the circulating port 41 and
into the casing annulus 24, where the fluid returns to the Earth
surface.
[0082] FIG. 6 depicts the cross-over assembly 25 for a reverse
state in which fluid may be communicated between the inner bore or
passageway of the tubing 18 and the annulus 24 as depicted by
bi-directional arrow 220. Thus, for this state, the cross-over
assembly 25 blocks fluid communication between the inner bore of
the tubing 18 and the service tool 20 below the gravel pack packer
32, and opens the circulating port 41 to establish fluid
communication between the inner bore of the tubing 18 and the
annulus 24.
[0083] As described in the examples discussed above, the sensors on
the sand control completion system 10 may be used for purposes of
monitoring and controlling various aspects of gravel
packing-related operations. These operations include operations
that occur prior to the beginning of the gravel packing operation
in which the gravel laden slurry is communicated downhole, the
gravel packing operation itself and operations after the gravel has
been deposited around the sand control section 46. Specific
exemplary, non-limiting uses of the sensors of the sand control
completion system 10 to control gravel packing-related operations
are described below.
Operations Preceding Gravel Packing
[0084] As a first example of an operation that precedes gravel
packing and may use the sensors, the mud/brine weight may be
monitored during the running of the lower completion section 30 to
ensure that the mud/brine weight maintains a certain degree of
overbalance. Fluid density may change with temperature and although
this relationship is understood, it may be difficult to accurately
determine the temperature profile. Therefore, downhole pressure
measurements acquired using sensors that are disposed on the sand
control completion system 10 may be used to directly measure the
overbalance and calculate the fluid density using depth in real
time. Based on the monitored pressure and calculated fluid density,
weighted fluid may then be displaced from the Earth surface to
correct any fluctuations in the pressure and ensure that the
pressure is at the desired level.
[0085] As another example of an operation that may be monitored
during the running of the sand control completion system 10
downhole, the work string 12 may become stuck during the running
and need to be worked free, i.e., pushed and pulled from the
surface repeatedly to free the string 12. However, exceeding the
tensile and/or compressive ratings of downhole equipment is a
concern. For example, exceeding the ratings may result in damage
(the splitting of sand screens, for example), which may be
detrimental to the sand control treatment. Although conventionally,
torque and drag modeling has been used to estimate downhole forces
from measured surface hook load, this modeling may be relatively
subjective and difficult to verify accurately. Therefore, large
safety factors have traditionally been built in, which
unnecessarily limits the forces that may be applied to free the
work string.
[0086] Therefore, by using the sensors on the sand control
completion system 10 to acquire force measurements along the system
10, the following measurements and control may be performed. First,
force measurements along the sand control completion system 10 may
be acquired to identify whether the work string 12 has become
stuck, as well as the specific location of the sticking point.
Torque measurements may also be acquired and monitored from the
surface in real time or near real time for purposes of identifying
the sticking point if the lower completion is being rotated. A
sensor that is disposed above the service tool 20 and another at
the end of the work string 12 may be used to provide information to
the operator at the Earth surface in real time or near real time
for purposes of identifying the location at which the work string
12 is stuck. The same sensors may be used, for example, to directly
measure the local downhole forces on the downhole equipment while
tensile and/or compressive forces are applied on the work string 12
in order to ensure that these forces are within the limits of the
downhole equipment.
[0087] The sensors on the sand control completion system 10 may
also be used to monitor washdown and circulation operations
involving the sand control completion system 10 prior to the
beginning of the gravel packing operation. During this operation,
the service tool 20 is manipulated up and down the borehole.
However, the end of the work string 12 may become stuck in an
openhole section due to collapse or swelling, for example; and as a
corrective action, fluid may need to be circulated through the wash
pipe 22 for purposes of removing the material that causes the
blockage and freeing the work string 12. Traditionally, washdown
operations have been performed at the highest flow rate possible
for purposes of effectively removing the material. However, if a
non-pressure sensitive (NPS) tool is used, the packer setting
mechanism is isolated, and the limiting rate is the minimum rate
that causes swabbing of the packer elements. If a standard tool
(i.e., not an NPS tool) is used, then the limiting rate is the rate
that causes the packer setting pressure inside the service tool 20
to be exceeded due to dynamic fluid friction.
[0088] Traditionally, the annular flow rate is measured at the
Earth surface with a flow meter and controlled accordingly; and
pressure inside the service tool may be estimated using friction
models. Safety factors are included to ensure that the packer is
not accidentally set in the wrong position, which means the maximum
possible rate is not utilized. However, by using one or more
downhole pressure sensors on the sand control completion system 10,
real time or near real time pressure reading may be acquired to
allow these pressures to be monitored at the Earth surface of the
well. In other words, the pressures may be monitored so that
operations may be controlled to maintain the packer setting
pressure below a certain threshold by adjusting the flow rate of
fluid into the well from the Earth surface. This allows the highest
flow rate possible and improves the chances of freeing the work
string 12.
[0089] One or more sensors of the sand control completion system 10
may be used to monitor the pressure that is being transmitted
downhole. In this regard, the pressure that is applied internally
inside the work string 12 to set the gravel pack packer 32 may not
be completely transferred downhole due to compressibility and the
yield effects of some fluids. It is noted that a minimum pressure
is applied to fully set the gravel pack packer 32. If this pressure
is not transmitted to the packer 32, the packer 32 is not set and
several attempts may be made, thereby potentially consuming a
significant amount of valuable rig time.
[0090] By using the pressure sensors of the sand control completion
system 10, the local pressure that is present downhole at the
gravel pack packer 32 may be monitored at the Earth surface in real
time or near real time so that the surface pressure may be
increased until sufficient setting pressure is achieved at the
gravel pack packer 32 on the very first attempt. In accordance with
some embodiments of the invention, the sand control completion
system 10 may include sensors inside the gravel pack packer 32
(sensors to indicate position of the thimbles or sealing rings, as
non-limiting examples) for purposes of confirming whether the
packer 32 has been set.
[0091] Pressure sensors on or near the gravel pack packer 32 may
also be used for purposes of pressure testing the packer 32. In
this regard, the downhole pressure that is created at the packer
for purposes of testing packer elements is not traditionally
completely known due to compressibility and yield effects of the
fluid. Moreover, pressure below the gravel pack packer when set
traditionally has not been exactly known as the region below the
packer is isolated by packer's annular seal. Therefore,
conventional pressure tests may not be entirely accurate.
[0092] However, by using sensors that deployed on the sand control
completion system 10, the precise local, downhole pressures and
more specifically, the precise differential pressures across the
packer's sealing ring may be monitored in real time or near real
time from the Earth surface. Therefore, an operator at the Earth
surface may take the appropriate measures (adjusting a flow rate of
a surface-disposed pump, for example) so that the downhole
pressure(s) are adjusted to meet the requirements of the test.
[0093] The pressure test also traditionally is conducted for
purposes of detecting leakage. In this regard, leakage may occur
around the packer's annular seal, through the casing string 16 or
even through Earth surface lines (a faulty valve, for example).
However, these leakages may be relatively difficult to identify,
which may incur a significant amount of valuable rig time.
Traditionally, the surface lines may be isolated and tested
independently to ensure that the leak is not there, which again
consumes valuable rig time; and leaking through the casing string
16 and various downhole elements may be relatively difficult to
discriminate from the surface pressure alone.
[0094] However, pressure sensors of the sand control completion
system 10, which are disposed below the gravel pack packer 32 may
be used to monitor the pressure below the packer 32 in real time or
near real time from the Earth surface for purposes of identifying
an increasing pressure (which indicates that the seal element of
the packer 32 is leaking) in response to an increase in the applied
pressure from the Earth surface. In this manner, if the leak is
occurring through, for example, the casing string 16 or the surface
lines, and the monitored pressure below the packer 32 is not
increasing, then a leaking packer 32 may be quickly eliminated as
the potential problem.
[0095] A push/pull test may be conducted on the work string 12
prior to the beginning of the gravel packing operation to determine
whether the gravel pack packer 32 is set. In a deep, or highly
deviated or horizontal well, it has traditionally been challenging
to determine how much force is being transmitted downhole due to
such effects as pipe buckling and friction against the casing
string. Therefore, traditionally, there may not be enough weight
being slacked off or picked up on the Earth surface to obtain a
proper test on the packer for purposes of determining whether the
packer is set. Therefore, a false positive may result if the weight
is actually being slacked off on the casing string, for example.
Conventionally, torque and drag modeling has been used to estimate
downhole forces from a measured surface hook load. However, this
modeling may be relatively subjective and difficult to verify
accurately.
[0096] In accordance with embodiments of the invention described
herein, however, the sensors of the sand control completion system
10 may be used to measure force in real time or near real time so
that this force may be monitored at the Earth surface for purposes
of providing an accurate measurement of the transmitted force so
that the surface hook load may be regulated to ensure that the
push/pull test is performed at the required downhole rating. The
sensors of the sand control completion system 10 may also be used
to acquire accelerometer measurements such that these measurements
may be monitored in real time or near real time at the Earth
surface to observe relatively small movements downhole, which may
be especially helpful in deep, highly deviated wells.
[0097] In the cased hole environment, a sump packer (not shown in
FIG. 1) supports the lower completion and a push test on the gravel
pack packer may be rather inaccurate. Additionally, if an anchor
latch is used with the sump packer, then the pull test may also be
relatively inaccurate. Therefore, under certain circumstances, it
may not have been traditionally possible to perform either a push
or pull test to verify that the slips are set, they are assumed to
be set if the packer pressure test is successful. Traditionally,
the weight on the packer is offset, and corresponding movement of
the string is observed from the surface to verify whether or not
the slips are set. In this manner, if no movement is observed, then
the slips are properly set. However, using sensors on the sand
control completion system 10, tension/compression measuring sensors
of the system 10, which are disposed on either side of the gravel
pack packer 32 may be observed in real time or near real time at
the Earth surface for purposes of determining whether the slips are
set.
[0098] The sensors on the sand control completion system 10 may
also be used to observe/confirm the release of the service tool 20.
In this regard, as a non-limiting example, pressure may be applied
internally to the work string 12 for purposes of releasing the
service tool 20. However, this pressure applied internally to the
work string 12 from the surface of the well may not completely be
transferred downhole due to compressibility and yield effects of
the fluid. It is noted that a minimum pressure is needed to release
the service tool 20.
[0099] If the appropriate pressure is not transmitted to the
service tool 20, then the service tool 20 does not release, and
several attempts may be made before using, for example, a backup
mechanical release, which, in turn, may consume a significant
amount of valuable rig time. Therefore, traditionally, the minimum
required pressure is applied at the Earth surface, and then a pull
up force is exerted on the work string 12. If the service tool 20
does not release, then this process is repeated with a higher
pressure up to a certain maximum pressure threshold. Eventually, if
the service tool is not released, then the string may be rotated to
release the service tool mechanically.
[0100] Unlike these conventional arrangements, however, pressure
sensors on the sand control completion system 10 may be used to
monitor the downhole local pressure that is present at the service
tool 20. Therefore, an operator monitoring this pressure in real
time or near real time at the Earth surface may increase the
pressure until the required release is achieved to release the
service tool 20 in the first attempt. It is noted that, in
accordance with some embodiments of the invention, sensors disposed
in the service tool 20 may be used to provide a real time or near
real time indication to the operator at the Earth surface whether
or not the service tool 20 has been released. As non-limiting
examples, the sensors may measure the position of the service tool
20 relative to the lower completion section 30, measure a relative
position of a collet that latches the service tool 20 in place,
etc.
[0101] It is noted that the pressure below the gravel pack packer
32 may have bled off to the formation, thereby creating a net
downward force on the service tool 20, and this force need to be
overcome for purposes of moving the service tool 20 uphole. In this
regard, if not enough weight is being picked up on the work string
12 to overcome this force, the incorrect impression that the
service tool 20 has not released may be observed. Thus, unnecessary
attempts may be made to release the service tool 20 or engage the
mechanical back up release of the service tool 20, which consume
valuable rig time.
[0102] Traditionally, the worst case pressure differential across
the service tool 20 is assumed, and the force to be applied to the
work string at the Earth surface is calculated accordingly, using,
for example, torque and drag modeling software. These measurements
may be relatively difficult to verify and may not be entirely
accurate. However, by using sensors on the sand control completion
system 10, the exact pressure differential that is experienced by
the tool 20 may be monitored at the Earth surface in real time or
near real time. The sensors may also allow the surface operator to
monitor the force that is applied to the service tool 20 to ensure
that the correct force is applied to the tool 20 downhole.
[0103] As described above, sensors may also be deployed on the
service tool 20 for purposes of indicating whether the service tool
20 has been successfully released, and sensors of sand control
completion system 10 may also be used to measure torque to verify
whether the service tool is being rotated in the event that the
mechanical backup release mechanism of the service tool 20 is
engaged.
[0104] Conventionally, during the movement of a service tool,
especially more complex service tools, it has been traditionally
been challenging to locate certain downhole positions quickly or
accurately. In this manner, the accidental shearing of collets may
make it very challenging to find a given position. Moreover, on
deep, highly deviated wells, it may be relatively difficult to
observe indications provided by location identifying collets on the
Earth surface, especially if the collets have become worn.
Furthermore, the heave on floating rigs may result in unintended
downhole movements that accidentally shear collets or move the
service tool out of position. The position of the service tool may
be relatively important in certain parts of the operation, such as
reversing out after screenout.
[0105] In accordance with embodiments of the invention, the sand
control completion system 10 may include one or more sensors to the
position of the service tool 20 so that the Earth surface operator
may monitor the actual position of the tool 20 in real time or near
real time without inferring the position from other measurements.
In this manner, one or more sensors on the sand control completion
system 10 may measure acceleration so that a second order
integration of the measured acceleration may be used to determine
the position of the service tool 20. It is noted that the initial
position of the service tool 32 may be inferred from the position
of the service tool 20 when the tool 20 is latched to the lower
completion section 30. The sensors may also acquire downhole force
measurements, which allow the Earth surface operator to observe
collect indications that may not be observable from the Earth
surface.
[0106] The movement of the service tool uphole may create a
swabbing effect in the wellbore above the gravel pack packer 32,
due to the fact that this region is isolated (i.e., a closed
volume). This may typically be a significant concern in open hole
completions. The swabbing creates a pressure reduction in the
wellbore which, on becoming lower than the reservoir pressure, may
create a suction to draw in fluid from the reservoir and damage the
filtering cake, which is placed along the openhole during drilling.
Therefore, the swabbing may create losses in the wellbore area,
which may have a detrimental effect on the sand control treatment.
Traditionally, anti-swab service tools are used for openhole
completions, which minimize this effect, although openhole
treatments may also be performed with standard tools, that do not
contain the anti-swabbing features. Even with an anti-swab service
tool, however, the service tool conventionally is moved relatively
slowly in order to allow the pressure to equalize throughout the
process.
[0107] By using sensors on the sand control completion system 10 to
monitor the downhole pressure, the pressure below the service tool
20 may be monitored in real time or near real time to allow this
pressure to be managed during the movement of the service tool 20
by varying the service tool's speed and even stopping, if needed.
Moreover, acceleration measurements acquired using the
accelerometers on the sand control completion system 10 may be used
to monitor the actual tool movement of the service tool 20 in real
time or near real time so that this movement may be controlled from
the Earth surface and kept within acceptable limits.
[0108] Sensors of the sand control completion system 10 may also be
used to detect the presence of pickle stages (gel caps, acid, etc),
which, if not for the measures described herein, may be
accidentally displaced through the service tool 20 and into the
annulus 34, which is not desirable. The pickle, in general, cleans
the work string 12 and picks up debris (rust, etc.) in the process,
which would otherwise settle on top of the packer seal elements if
pushed into the annulus and may introduce problems in retrieving
the packer 32 as well as contribute to the sticking of the service
tool 20. In this regard, the acid may attack the packer's seal
element and cause damage, thereby resulting in a leak that would be
detrimental to the gravel pack and future operations.
[0109] Traditionally, the workstring pickle has been performed with
the service tool in the reverse position, pumping the pickle down
the workstring to within 100 to 200 feet from the top of the gravel
pack packer before reversing the pickle back to the Earth surface
through the annulus. Displacements are therefore calculated
theoretically assuming that the piston/block fluid interfaces and
flow. However, these calculations may not be entirely accurate. In
this manner, roping, u-tubing and non-uniform displacements may
result in fluid stages arriving at the packer earlier than
expected.
[0110] Therefore, in accordance with embodiments of the invention
disclosed herein, one or more fluid property sensors of the sand
completion system 10 (sensors disposed on the tubing 18, for
example) acquire downhole rheology/viscosity/density measurements
so that these measurements may be communicated to the Earth surface
of the well in real time or near real time to allow the surface
operator to determine when fluid stages arrive downhole due to
detected fluid property changes. These measurements may also be
used to account for roping and non-uniform displacement effects,
which cause the fluid to arrive earlier than expected
theoretically, ensuring that pumping is stopped at the surface
before the pickle is displaced into the annulus 34. It is noted
that in accordance with other embodiments of the invention, the
stages may be detected using pressure and temperature readings that
are provided by temperature and pressure sensors of the sand
control completion system 10, although more indirectly. Moreover,
in accordance with some embodiments of the invention, one or more
of the sensors of the sand control completion system 10 may measure
pH, which allow the surface operator to determine the location of
the acid.
[0111] The sensors of the sand control completion system 10 may
also be used by the surface operation to determine whether a
certain fluid or fluids are completely displaced from a given
section. Fluid displacements typically are conducted to ensure that
chemically incompatible fluids do not contact one another. However,
a fluid may not be completely displaced from the section due to
non-uniform displacements, losses or rates too low to achieve
turbulence. If the fluid is not completely displaced, the fluid may
have a negative effect on a latter part of the operation.
[0112] Traditionally, the fluids are displaced using a flow that is
introduced at the surface at the highest possible rate to achieve
turbulence, subject to the rate being limited to ensure that an
estimated downhole pressure does not exceed a threshold. Moreover,
safety margins typically are introduced, which further limit the
rate. However, by using fluid property measurements (rheology,
viscosity, density, etc.) that are provided by the fluid property
sensor(s) of the sand control completion system 10, these
measurements may be monitored in real time or near real time from
the Earth surface to directly measure the displacement and mixing
of different fluids.
[0113] Pressure may also be acquired by one or more sensors of the
sand control completion system 10 for purposes of ensuring that
equipment limitations and fracturing pressures are not exceeded,
thereby allowing the maximum flow rates be pumped for effective
displacement. In this manner, the rates may be adjusted from the
Earth surface for purposes of achieving complete displacement. The
sand control treatment model may be calibrated using data conducted
from step rate tests. Traditionally, certain variables of the model
have been calibrated using Earth surface-acquired pressure
magnitudes and trends. However, these measurements have not
considered bottomhole pressures, due to the data being previously
available. Using pressure measurements acquired by the sensor(s) of
the sand control completion system 10, bottomhole conditions may be
accurately monitored at the Earth surface in real time or near real
time so that the sand control treatment model may be calibrated
using surface-acquired as well as these downhole-acquired
measurements. Therefore, a more accurate model may be obtained.
[0114] One or more sensors of the sand control completion system 10
may also be used to provide the Earth surface operator with
indications whether various problems have occurred with the step
rate test. For examples, these problems include restriction in the
system, debris in the service tool, wellbore collapse, screen
plugging, and so forth. Depending on where the restriction is
located, the restriction may have different effects on the
operation. For example, a restricted flow through the cross-over
assembly 25 may create a relatively high risk of screening out at
the cross-over port. Wellbore collapse or shale swelling may
increase the risk of bridging, while screen plugging prevents the
formation of a tight pack in the corresponding section.
Conventionally, step rate tests are performed at multiple rates in
reverse and circulating positions of the service tool for purposes
of gauging the surface pressure. In this manner, the measured
surface pressure has conventionally been compared to surface
pressures measured in similar wells for purposes of obtaining a
relative idea of the magnitude.
[0115] Although a relatively high surface pressure may indicate a
restriction, this indication alone does not identify the location
of the restriction. However, using downhole pressure measurements
acquired by one or more sensors of the sand control completion
system 10, downhole pressure measurements may be used to identify
exactly where a restriction is located downhole due to the
increased friction at that point. For example, a wellbore collapse
shows additional pressure drop in that section of the openhole
only. Similarly, debris in the service tool 20 is indicated by the
detection of friction there but not in the open hole.
[0116] Depending on the scenario, a corresponding action may be
taken from the Earth surface based on the real time or near real
time pressure measurements. For example, debris in the service tool
20 may result in the operator pulling the string 20 out of hole and
running a backup service tool instead. Wellbore collapse provides
an indication of where bridging occurs in a shunt tube job so that
the job may be designed correspondingly. For open hole water
packing jobs (i.e., no shunt tubes), the operator may rectify the
situation before proceeding.
[0117] One or more sensors of the sand control completion system 10
may also be used to identify locations where fluid losses are
occurring in the well. In this regard, fluid losses occur when the
fluid return rate is less than a fluid pump rate at the Earth
surface. These losses may cause bridging during the gravel pack
treatment, which may terminate the job completely or force fluid
through the shunt tubes (if used). Losses at the heel of the well
may have a far different effect than losses at the toe of the well.
However, conventional systems do not permit discrimination as to
the precise location of the fluid losses.
[0118] One or more sensors of the sand control completion system 10
may, however, be used to allow multiple downhole rate measurements
to be acquired along the screens or sandface; and these
measurements may be monitored by the surface operator in real time
or near real time to identify where losses are occurring. As
described above, these rate measurements may be acquired directly
or may be acquired indirectly using pressure or temperature
measurements. In general, losses at the heel of the well may be far
more detrimental to the sand control job than losses at the toe, so
the measured rate measurements permit an informed decision to be
made. The location of any potential bridging may also be therefore
determined and considered when pumping the treatment.
[0119] Thus, referring to FIG. 7, a technique 300 includes running
(block 304) a sand control completion system into a well and using
(block 308) the system to prepare the well for an upcoming gravel
packing operation in which the system is used to communicate a
slurry downhole and form a gravel pack around a lower completion.
At the Earth surface of the well, parameters that are sensed by
sensors disposed on the system are monitored in real time or near
real time, pursuant to block 312; and in response one or more of
the monitored parameters, the running of the system into the well
and/or the use of the system to prepare the well for gravel packing
is regulated, pursuant to block 316.
Gravel Packing Operation
[0120] The sensors of the sand control completion system 10 may be
used for purposes of monitoring the actual gravel packing operation
in which a gravel-laden slurry is communicated downhole through the
work string 12, the carrier fluid returns uphole via the annulus 24
and the gravel is deposited about the sand control section 46 (see
flow 210 of FIG. 5, for example). In this manner, one or more
sensors of the sand completion system 10 may be used to monitor a
variety of downhole parameters during the gravel packing operation
in order to allow the operator at the Earth surface of the well to
take any appropriate action to regulate the gravel packing
operation.
[0121] As a non-limiting example, one or more pressure sensors of
the sand control completion system 10 may be used to monitor a
screenout pressure. In this scenario, the screenout pressure below
the gravel pack packer 32 may be monitored in real time or near
real time at the Earth surface and may be used to anticipate the
screenout. It is noted that the screenout may be a premature
screenout due to bridging and resulting in shunt activation. Based
on the monitored screenout pressure, the slurry flow rate and
proppant concentration may be regulated from the Earth surface in
order to ensure that the screenout is achieved within the
limitations of the equipment and system downhole. This control
scheme removes the need for large safety factors when designing the
well and choosing the appropriate equipment, potentially reducing
cost, complexity, etc.
[0122] As another example, the operator may monitor parameters in
real time or near real time provided by one or more sensors of the
sand control completion system 10 for purposes of monitoring for a
condition called "roping." In general, roping results in the slurry
stages arriving bottomhole earlier than expected volumetrically.
Although traditionally, models may be used to predict roping, these
models may be relatively inaccurate, due to the inability to
conventionally monitor the actual downhole conditions. However, by
using one or more sensors on the sand control completion system 10,
fluid properties may be monitored at the Earth surface in real time
or near real time to detect changes in fluids so that the arrival
of certain fluid stages downhole may be accurately measured.
Moreover, pressure measurements provided by certain sensors of the
sand control completion system 10 may also be used for this
purpose. This allows the surface operator to know exactly when
certain trends or changes are expected and react accordingly, such,
for example, by changing the rate at which fluid is pumped
downhole.
[0123] During the gravel packing operation, the service tool 20 may
be forced up out of position during high pressure pumping due to a
net upward force that is exerted on the tool 20. If the circulating
port 41 (see FIG. 5, for example) moves into the gravel pack packer
32, there is sudden unexpected pressure increase that may damage
downhole equipment. In an open hole water packing treatment, such a
scenario may terminate the job due to screenout at the cross-over
assembly 25.
[0124] Traditionally, calculations may be made (based on
simulations and pressure predictions, for example) for the worst
case scenario for the net upward force exerted on the service tool
20 during the treatment. A weight is set down on the service tool
20 using torque and drag modeling to calculate this from the
surface hook load. However, these procedures typically involve
assumptions and are difficult to verify accurately. By using one or
more sensors of the sand control completion system 10, the service
tool's position may be monitored indirectly or directly in real
time or near real time at the Earth surface for purposes of
allowing the surface operator to detect when the service tool 20 is
moving and even calculate the distance that the service tool 20 has
moved in real time. One or more sensors of the sand control
completion system 10 may also be used to measure a net force that
is exerted on the service tool 20, which obviates the need to
calculate this force based on assumptions.
[0125] If due to these measurements, the surface operator observes
a movement in the service tool 20, more weight may be set down from
the surface to push the service tool 20 back into the appropriate
position.
[0126] One or more sensors of the sand control completion system 10
may be used to monitor for the occurrence of bridging (packing
occurring in an unexpected place) during the gravel packing
operation. In an open hole water packing job, bridging may end the
job prematurely and prevent the area beneath the bridge from being
packed. In a job involving shunt tubes, bridging may force fluid
through the shunt tubes, which means that the surface
rates/pressures are subsequently controlled to ensure that the
limitations of the shunt tubes are not exceeded.
[0127] More specifically, in accordance with some embodiments of
the invention, pressure sensors that are disposed along the sand
control assembly 46, such as the sensors 70 (see FIG. 1, for
example), measure pressures (which are communicated to the Earth
surface in real time or near real time) to identify which section
is being packed through changes in friction, which are indicated by
the pressure measurements. Monitoring of the bridging may be useful
in multi-zone and openhole isolation jobs where there may be
multiple sections that are simultaneously packing. If bridging is
observed, the surface operator may take the appropriate measures to
limit, prevent or delay the bridging, such as increasing or
decreasing the rate at which the slurry is pumped downhole, for
example.
[0128] One or more sensors (such as pressure sensors, for example)
on the sand control completion system 10 may be used for purposes
of allowing the surface operator to monitor whether a hole forms in
the sand control section 46 (see FIG. 1, for example) during the
gravel packing operation. For example, a hole may form in a sand
control screen. A hole in the sand control section 46 allows gravel
to displace into the wash pipe 22 (see FIG. 1) and into the casing
annulus 24 above the packer 32, which risks significant equipment
damage as well as the possibility of the service tool 20 becoming
stuck. Traditionally, it is relatively difficult to observe that
hole has formed in the sand control section, as it is usually
discovered when there is no screenout but a significant amount of
gravel is reversed after the treatment. At this point, the risk has
been taken unknowingly and damage may or may not have occurred.
[0129] In accordance with some embodiments of the invention, the
surface operator may determine whether a hole has formed in the
sand control section 46 based on pressure measurements that are
acquired by the sand control completion system's sensors. The
packing mechanism may be completely different to the mechanism that
is expected, as it takes place inside the screens and thus, may be
detected early on using such pressure sensors. Acceleration
measurements acquired by accelerometers placed on the sand control
completion system 10 may also be used to detect the presence of
gravel inside the screens.
[0130] After the surface operator identifies the formation of a
hole in the sand control section 46 in real time or near real time
using the sensors, the operator may then stop the job and reverse
the slurry out before the slurry enters the casing annulus 24.
Other remedial measures includes pulling the sand control
completion assembly 46 out of hole or other remedial
treatments.
[0131] One or more sensors on the sand control completion system 10
may be used, in general, to observe at the Earth surface whether
the gravel packing operation has proceeded as planned.
Traditionally, a successful gravel packing operation may not be
confirmed until the service tool is pulled out of hole and data
from any memory gauges of the tool are downloaded and analyzed.
However, because the sand control completion system 10 allows data
to be monitored at the Earth surface in real time or near real
time, the operator has the peace of mind knowing that everything is
going well throughout the treatment. Moreover, the next phase or
operation for the well may be planned even before the service tool
20 has been retrieved from the well.
[0132] Thus, referring to FIG. 8, a technique 350 in accordance
with embodiments of the invention disclosed herein includes running
(block 354) a sand control completion system into a well and using
(block 358) the system to perform a gravel packing operation in
which the system is used to communicate a slurry to form a gravel
pack around a lower completion. At the Earth surface of the well,
sensors that are disposed on the system are monitored in real time
or near real time, pursuant to block 362. The technique 350
includes, in response to one or more of the monitored parameters,
regulating (block 366) the gravel packing operation to control a
screenout pressure and/or control positioning of a service tool of
the system.
Operations Proceeding Gravel Packing
[0133] One or more sensors of the sand control management system 10
may also be used to monitor operations that occur after the gravel
pack has been formed. For example, in accordance with some
embodiments of the invention, one or more sensors of the sand
control completion system 10 may be used to monitor in real time or
near real time the pressure of the casing annulus 24 while the
service tool 20 is being moved to prevent u-tubing into the annulus
24. In this regard, gravel in the casing annulus 24 may cause the
service tool 20 to become stuck in the packer bore during movement.
If the service tool cannot be freed, relatively extreme action may
be needed, such as chemical cut or even a side track.
Traditionally, the theoretical hydrostatic difference in pressure
between the tubing and annulus is calculated, and then an
additional safety margin (500 pounds per square inch (psi), for
example) may be added. However, these calculations assume ideal
displacements and do not account for roping effects and non-uniform
displacements. By using one or more sensors of the sand control
completion system 10 to measure pressure, the exact hydrostatic
pressure on screenout may be monitored in real time or near real
time from the Earth surface. Therefore, the correct pressure may be
applied without the need to add excessive safety factors.
[0134] One or more sensors of the sand control completion system 10
may also be used to detect and free the work string 12 if the work
string 12 becomes stuck when going to reverse out position. In this
manner, without the use of the sensor(s), it may not be possible to
determine precisely the location at which the work string 12 is
stuck. In this manner, the work string 12 may be stuck at the wash
pipe 22, at the service tool 20, etc. Therefore, it is unclear as
to how much upward force may be exerted on the work string 12
without exceeding the stuck component's tensile rating. Therefore,
traditionally, it is assumed that the component of the work string
12, which has the minimum tensile rating is stuck; and the work
string 12 is worked within those limits. If the work string 12 is
not freed, then the exerted force is increased to the next lowest
minimum tensile rating, etc.
[0135] Torque and drag modeling traditionally has been used to
calculate the downhole force from the surface-applied force.
However, this modeling may not be accurate or verifiable.
Therefore, by using one or more sensors disposed on sand control
completion system 10, several determinations may be made in real
time or near real time: first, the component that is stuck may be
identified by, for example, pulling upwardly on the work string 12
and then measuring the force at various points downhole to see
where it is being transmitted; and secondly, the work string 12 may
then be worked within the limits of the stuck component's maximum
tensile rating by adjusting the surface force to get the required
force downhole, as measured directly downhole and provided to the
surface operator.
[0136] One or more sensors of the sand control completion system 10
may further be used to monitor and regulate the removal of the
filter cake and/or an acid treatment. In this manner, although
fluid may be communicated downhole through the end of the wash pipe
22 for the removal of filter cake, the filter cake and gravel pack
fluid may not be effectively cleaned up, which results in reduced
retained permeability and increased skin, which have negative
effects on subsequent production.
[0137] Traditionally, the workstring is moved up and down along the
sandface while pumping the treatment to ensure that the treatment
is spotted along the entire interval. However, it is not possible
to know exactly where the fluid is being communicated, especially
if there are losses somewhere along the wellbore. Although
traditional equipment may contain memory gauges that may provide an
indication as to this condition, the string is already retrieved
from the well when the data is retrieved from the gauges. However,
using the sensors of the sand control completion system 10, fluid
changes may be detected by corresponding pressure, temperature or
fluid property measurements acquired by the sensors such that an
operator at the Earth surface may monitor in real time or near real
time where a given fluid is being communicated downhole in the
well. Therefore, the operator may adjust the rate of fluid being
pumped into the well and/or position the wash pipe 22 more
accurately to treat the required interval. The remedial action may
also include, in certain cases, pumping diverting agents or similar
corrective fluid downhole to direct the fluid.
[0138] The sensors of the sand control completion system 10 may
also be used to monitor the work string 12 when the string 12 is
pulled out of hole, or retrieved from the well. In this manner, as
described above, the various sensors of the sand control completion
system 10 may monitor the forces present on the string 12 during
removal, etc.
[0139] Thus, referring to FIG. 9, a technique 400 in accordance
with embodiments of the invention includes using (block 404) a
downhole sand control system to perform a downhole gravel packing
operation to form gravel pack around a lower completion. At the
Earth surface of the well, parameters that are sensed by sensors
disposed on the system are monitored in real time or near real
time, pursuant to block 408. After formation of the gravel pack,
the technique 400 includes performing (block 412) one or more
subsequent operations using the system before pulling the service
tool of the system from the well, pursuant to block 412. In
response to the one or more monitored parameters, the technique 400
includes regulating (block 416) one or more of the subsequent
operations.
[0140] While the present invention has been described with respect
to a limited number of embodiments, those skilled in the art,
having the benefit of this disclosure, will appreciate numerous
modifications and variations therefrom. It is intended that the
appended claims cover all such modifications and variations as fall
within the true spirit and scope of this present invention.
* * * * *